Solved leetcode 1002 and 771

Author: codethecoffee

1002-Find Common Characters.py

@@ -0,0 +1,57 @@
+# Link to problem: https://leetcode.com/problems/find-common-characters/
+
+def commonChars(A):
+    length = len(A)
+    
+    # Edge case: Only one string given; return all characters in it
+    if length == 1:
+        return list(A[0])
+    
+    # Dictionary to hold characters common amongst all strings
+    common_chars = {}
+    
+    # Populate common_chars with the character count of the first word
+    for char in A[0]:
+        if char in common_chars:
+            common_chars[char] += 1
+        else:
+            common_chars[char] = 1
+    
+    for i in range(1, length):
+        curr_word = A[i]
+        
+        # Shallow copy of the current common characters so far
+        # We will update the contents of this dictionary
+        curr_chars = common_chars.copy()
+        
+        # Only update for characters already in curr_chars
+        # We only care about the common characters, so don't
+        # create new entries for newly encountered chars
+        for char in curr_word:
+            if char in curr_chars:
+                curr_chars[char] -= 1
+        
+        for key, val in curr_chars.items():
+            old_com = common_chars[key]
+            
+            # Exact same number of instances as common_chars, or more.
+            # Keep the original common_chars entry
+            if val <= 0:
+                continue
+            # No instances of the common char in this word; remove from
+            # the common_char dictionary
+            elif val == old_com:
+                del common_chars[key]
+            # Some non-zero number of instances of the char, but less than
+            # the common_chars
+            else:
+                common_chars[key] = old_com - curr_chars[key]
+    
+    # Parse the common_chars dict into proper final format
+    ans = []
+    
+    for key, val in common_chars.items():
+        for _ in range(val):
+            ans.append(key)
+    
+    return ans

771-Jewels and Stones.py

@@ -0,0 +1,10 @@
+# Link to problem: https://leetcode.com/problems/jewels-and-stones/
+
+def numJewelsInStones(self, J: str, S: str) -> int:
+    num_jewels = 0
+    
+    for char in S:
+        if char in J:
+            num_jewels += 1
+    
+    return num_jewels